This invention relates generally to wheelchair brake assemblies and particularly to an assembly which is released automatically when the user becomes seated.
Conventional wheelchairs of the type which are folded for storage purposes are invariably fitted with hand-operated brakes. These brakes engage the main drive wheels of the wheelchair, and are applied by the user, or a helper, before the user is seated in the wheelchair so that the wheelchair is stabilized. The brakes are released by hand once the user is seated to permit the wheelchair to become mobile. They are re-applied when the user wishes to leave the wheelchair.
Brakes of this conventional type are adequate when the user is not seriously physically handicapped and is in complete control of his mental faculties. However, when the user is handicapped to the point of being unable to operate the hand brake they are quite inadequate. A seriously handicapped user, attempting unaided to get into a wheelchair which is not locked into a stationary position is faced with a difficult and dangerous task. Further, an unbraked wheelchair, which is used as a temporary support to assist in walking also presents a serious hazard to the user.
Because of this, attempts have been made to provide an alternative system which remains in a braked condition automatically when not being used, until the user becomes seated. When the user becomes seated the brake is released by the weight of the user.
The most pertinent known disclosure of a wheelchair braking system of this type is to be found in U.S. Pat. No. 3,529,700. This system relies for its operation on the use of chains or rod linkages which are connected between a set of rigid actuating bars attached to the seat panel, and such linkages operate a pair of transverse brake levers which engage the main wheels.
The present brake assembly represents an improvement over this and other known systems as will now be described.